Hydronic (water-sourced) systems create heat energy by heating water and transporting it throughout the house. Common examples of hydronic systems include hot-water heaters. A pump circulates the hot water from your hot-water heater to a hydronic coil connected in parallel with your air conditioning system.
Hydronic radiant floor heating systems use a boiler or district heating to heat water and a pump to circulate the hot water in plastic pipes installed in a concrete slab. The pipes, embedded in the floor, carry heated water that conducts warmth to the surface of the floor, where it broadcasts heat energy to the room above. Hydronic systems circulate hot water for heating.
Steam heating systems are similar to heating water systems, except that steam is used as the heating medium instead of water. Hydronic heating systems generally consist of a boiler or district heating heat exchanger, hot water circulating pumps, distribution piping, and a fan coil unit or a radiator located in the room or space. Steam heating systems are similar, except that no circulating pumps are required. Hydronic systems are closed loop: the same fluid is heated and then reheated. Hydronic heating systems are also used with antifreeze solutions in ice and snow melt systems for walkways, parking lots and streets. They are more commonly used in commercial and whole house radiant floor heat projects, whereas electric radiant heat systems are more commonly used in smaller “spot warming” applications.